Astronauts Nicholas Patrick and Robert Behnken successfully completed their five hour, 54 minute spacewalk at 3:14 a.m. EST, and finished all the scheduled tasks.
In their second spacewalk in three days, the spacewalk specialists fixed four long hoses to the space station's new Tranquility node, thus completing the activation work at the node.
As the spacewalkers successfully hooked the hoses, they were able to power up the newest space room.
The Mission Control reported the good news saying that temperature level was dropping in Tranquility and power was kicking in.
Slight ammonia leak during work
While doing the space plumbing work, Patrick was hit with leaked ammonia but none of the toxic drops were stuck to his suit.
The ammonia leak could have posed great threat if it was released inside the station.
Patrick defined the frozen drops of ammonia as puff of snowflakes. "It was about the kind of quantity of stuff that you would expect if you didn't empty the straw at the end of your drink bag," he reported.
The Mission Control said that ammonia leak was not surprising, as slight leakage was expected.
As a preventative measure, Patrick got his suit inspected by Behnken, but no drops of ammonia were spotted.
"You look clean to me," Behnken said. "Thank you Bob, good news,” replied Patrick.
More work to be completed
Patrick and Behnken will now undertake another spacewalk to complete the work on the Tranquility module.
The Tranquility node, once completed, will become the most advanced life support system on space. It will recycle waste water at the International Space Station and will generate oxygen for the crew.
Since the astronauts were not able to install a center disk cover at the hatch on Saturday due to interference with the lock-down bar, the astronauts will spend an extra day at the space station to complete this work. The center disk cover is essential because it protects the docking interface from temperature extremes and debris when no module is connected to it.
The space walkers will also move two Water Recovery System racks, the Waste Hygiene Compartment and the Oxygen Generation System into the Tranquility node.
After completing the assigned tasks, Endeavour will return to Earth Sunday night, Feb. 21.